A civilian D.C. police oversight board says Police Chief Cathy L. Lanier has three times since 2010 ignored its findings of officer misconduct and refused to dole out any punishment.

Although the department’s rejection of a panel’s finding comes in only a small fraction of cases, the board’s director says it undermines the group’s credibility and sets a precedent to undo legally binding decisions.

The Office of Police Complaints also said in its annual report that more than one-third of the 64 D.C. officers involved in disciplinary cases handled by the board last year refused to cooperate with investigators. That is a sharp increase from 2010, when three declined to provide their versions of events.

“We want the chief to have some control over her troops,” said Philip K. Eure, executive director of the mayor-appointed board. “But there’s a process, and you have to respect the law. The [police department] has done that in the vast majority of cases. . . . But we do have differences of opinions at times. We’re doing our job.”

Lanier said she’s asking the D.C. attorney general to weigh in on whether she has to reprimand or suspend an officer in cases in which “our disciplinary review does not feel there is evidence to support the outcome.”

“Are we required to discipline a member who we don’t feel deserves it?” she asked, noting that she has made only three reversals.

In its annual report, the complaints board called this practice “troubling” and said “it was made in direct conflict with District law stating that the decision of a final review panel ‘shall be binding on the subject police officer or officers and on the police chief.’ ”

Lanier also said some officers are resisting cooperating with the panel because they don’t want to risk self-incrimination should they later be investigated by prosecutors. Lanier said she wants clarification from the attorney general on whether the civilian panel can grant officers limited immunity that would prohibit prosecutors from using their statements in a criminal case.

The Office of Police Complaints was formed by statute in 2001 as an alternative to the department’s in-house investigations squad, the Internal Affairs Bureau. The civilian board typically investigates allegations of improper use of force, bad language and rude behavior. It has more teeth than similar panels in other cities in that it has subpoena power. An assistant D.C. police chief is on the board.

Eure, a former lawyer in the U.S. Justice Department, said police first rejected the panel’s finding three years ago in a case in which an officer used inappropriate language. He said the department indicated the dismissal was done in error.

The annual report says the department dismissed two more cases last year. In one, involving profanity and harassment, Lanier declined to punish one officer but issued mild reprimands to two others in the same incident.

In another case, Lanier exonerated an officer after the panel concluded the officer arrested someone without justification and used inappropriate force, taking a suspect to the ground by his neck.

In that instance, Lanier had filed an appeal of the board’s decision, but a three-member panel ruled against her. According to the annual report, Lanier said she thought investigators relied too heavily on the version given by the man arrested and by his friends.

Eure said that after losing the appeal, Lanier ignored the ruling, which he believes she cannot do. “We consider these to be serious matters warranting further scrutiny,” the annual report says.

The Office of Police Complaints is just one place for people to lodge objections about police conduct. Internal affairs can investigate the same type of issues as the civilian panel, as well as more serious allegations involving violations of criminal laws, police-involved shootings and corruption.

In 2011, the most recent year for which statistics are available, internal affairs investigated 386 complaints, including 22 alleging false arrest, 67 accusing rude or unprofessional behavior, 38 involving abuse of authority and four regarding excessive force. More than 50 complaints were sustained, according to the department’s annual report, though a breakdown was not provided.

The Office of Police Complaints received 574 formal inquiries in fiscal 2012. Twenty-one other cases were determined serious enough to warrant a full investigation. Twelve resulted in a finding of misconduct against at least one officer involved in the case.

Four officers received minor letters of prejudice, which typically means guidance and counseling; two more got serious letters of reprimand, which can impact performance reviews and promotions; and two were found guilty of dereliction of duty. Two officers were suspended, the most serious discipline. One for 10 days, another for 30 days, for punching a man in the face after he shouted a profanity and clenched his fists by his side.